Multiple-bar gluing clamp



Jan. 20, 1953 M. E. WETZLER MULTIPLE-BAR GLUING CLAMP 3 Sheets-Sheet 1 Filed Sept. 16, 1949 MAX 5. WETZLER INVENTOR l W W 4% I HlllmLl Arm/way Jan. 20, 1953 M. E. WETZLER 2,625,970

MULTIPLE-BAR GLUING CLAMP Filed Sept. 16, 1949 3 Sheets-Sheet 2 MAX E. WETZLE/P INVENTOR.

ATTOR/Vi'V Patented Jan. 20, 1953 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to clamps, and more particularly to clamps used for gripping two or 'more sections of wood, laminated wood, or a similar material, the adjoining edges of which are glued or fastened by other means, to retain the parts in position while the glue or other adhesive'dries.

The clamps may also be set up in multiple tiers, to enable two or more sets of work pieces to be clamped simultaneously.

Because of the wide range of thickness and width of the pieces to 'be clamped, the bars are adjustably held in such a manner as to readily accommodate pieces varying in thickness, and to readily adjust the clamping mechanism to hold -pieces over a range of widths.

It-is further essential that the gripping mechanism, which holds the clamping jaws against the bars, be capable of rapid adjustment for spacing, andthat they be capable of tightly gripping the bars in any clamping position.

The object of my invention is to provide a multiple-bar gluing clamp, which will readily accommodate a wide range of Work-piece thicknesses.

A further object is to provide a clamp which may b rapidly adjusted to clamp material over a range of widths.

Another obj ectis to-provide a clamping mechanism which can be utilized in'multiple, so that a number of sections of work-pieces can be '"clampedand tiered, simultaneously to occupy 'a minimum of space, each set of pieces being individually clamped.

"iii-further object is to provide a clamp, the jaws "of which are 'angularly adjustable, so as to take upirregularities and variations in parallelism of 'the'work-pieces, without difilculty.

Another object is to provide a clamping unit,

which is rugged in construction, and will function in dusty atmospheres, the parts in which are'so constructed that the operation is not seriously affected by small quantities of dried glue,

"or other 'minor' obstructions which may accu- "mulate on the clamp in this type of work.

A fundamental object is to provide a clampingunit, in which the parts are readily interchangeable, easily assembled, fitted and disas- The accompanying drawings, illustrative of one embodiment of my invention, and several modifications thereof, together with the description of their construction and the method .of operation thereof, will serve to clarify further objects andadvantages of myiinvention.

In the drawings:

Fig. :1 represents a front elevation of the assembled clamp, showing the jaws the-clamping position.

Fig. 2 is a plan view of thfi clamp assembly of Fig. 1, with the eccentric cams shown in the released position, before the jaws are tightened.

Fig. 3 is a partial cross-section throu h the bracket, taken at 3+3, Fig. 1, showing the eccentric cams in the gripping position, with relation to the bars.

.Fig. 4 is a partial side elevation of the clamp of Figs. 1 and 2, and .a partial vertical section, taken at 44, Fig. 3,.

Fig. 5 is a side elevation of the bar' slide and adjusting screw bracket, taken at 5.5, Fig. 1.

Fig. 6 is amodifiedxperspectiye view of .a plurality of multiple-bar clamps, tiered to :support a number of workpieces, one between'the'cdges of each pair of .bars.

It will be understood that the following description of the construction and operation of bar and bracket being oonnectedby a-rivet 14,

or other suitable 'means of attachment. The adjacent end of the other bar may be slida'bly fitted into a slot 15, formed in the upper endof the bracket, the opposite end of the bars being slidably fitted into two slots 16 and H, formed at opposite-ends of a sliding bracket -I 8, mounted at the opposite end of the clamp, as indicated in Figs. 1 and 4.

The :work pieces 2 Band =2- l of wood, laminated wood, or other similar materials, having a glued or other type of adhesive joint 22, formedbetween adjacent edges thereof, are held in the clamping position, between the "bars, during the processof drying, by an adjustable jaw'23yrotatably mount d at the free end of a long, substantially cylindrical adjusting screw 24, having square, Acme, or other suitable form of threads 25 cut through the outer circumference thereof, the threads being fitted to an opening 26, formed in the bracket l2, between the bars, with the opposite end of the work-pieces held against a floating jaw 21, adjustably supported by two substantially parallel pins 28 and 29, the ends of each of which is trunnioned in an opening 30, formed in each of the cams, in two sets of eccentric cams 3| and 32, positioned and rotatably supported in two substantially parallel slots 33 and 34, formed in the sliding bracket IS.

The inner, or eccentric portion of the eccentric cams, may be trunnioned on two substantially parallel pins 35 and 36, rotata'bly supported in openings formed in the sliding bracket I8, the pins being substantially parallel to the outer pins 28 and 29.

When the clamp jaws are in the open position, shown in Fig. 2, the pins 28 and 35 may be located in substantial alignment with one another, or the outer pins 28 and 29, may be located slightly forward or rearward of the inner pins 35 and 36, the

gripping edges 31 and 38, of the eccentric portion of the cams, clearing the faces of the bars I8 and II, to allow the cams and the bracket to be slid along the bars.

When the adjusting screw 24 is manually rotated "by means of a control handle 39, attached to the against the outer pins 28 and 29, thus moving the pins into the clamping position, shown in Fig. 3, the cams being rotated about the pivot pins 35 and 36, until the arcuate clamping surfaces 3'! and 38,

-of the eccentric cams 3| and 32, are pressed tightly against the opposite surfaces of the bars,,thus gripping the bars between them, as indicated in .Fig. 3.

In order to reduce the distance between the bars I8 and II and accommodate thin workpieces, a pair of slots 48 may be formed in the clamping wall 42, of the floating jaw, to clear the -inner edges of the bars, as indicated in Figs. 1 and 2.

V The maximum range of the thickness of the work-pieces, which may be supported in a clamp of. a particular size, is determined by the depth of the slots l5, l6, and H, in the fixed bracket l2, and the sliding bracket l8, respectively, in which the bars are slidably supported, and the distance between the upper and lower eccentric cams 3| and 3|a, and 32 and 32a, which grip the faces of the respective bars in the clamping position.

The clamping faces of the eccentric cams 3| and 32 grip the bars with equal facility, regardless of the position of the cams, with relation to the surfaces of the bars, as the gripping edges of the cams are substantially perpendicular to the bar faces.

A pin 49 may be fitted through an opening formed in the rear end of the sliding bar II], the ends of the pin, which project through the bar, engaging the rear face 50, of the fixed bracket [2,

to limit the forward movement of the bar, when the adjusting screw is rotated into the clamping position.

The rear face 50, of the upper portion of the bracket l2, may be sloped inward from the top of the bracket to approximately the center thereof, to press the pin and the upper bar downward toward the work-pieces, when the projecting nds of the pin 49 are pressed against the bracket face in the clamping position.

The contour of the clamping surface, of the cocentric cams 3| and 32, may be substantially circular, with the center a short distance from the center of the opening 5|, which fits one of the inner pins 35 or 36, thus obtaining the eccentric action and gripping pressure against the bars, when the outer pins 28 and 29 are moved into the clamping position, shown in Fig. 3. The center distance may be increased or decreased to vary the gripping pressure against the bars, or the contour of the clamping surfaces 3! and 38 may be altered to obtain a cam contour, to increase or decrease the rate of application of the gripping pressure, or to vary the angular movement of the eccentric cams from the free position, shown in Fig. 2, to the gripping position shown in Fig. 3.

The distance between the parallel faces 52 of the elongated slots 43 and 44, formed in the floating jaw may be made greater than the diameter of the pins 28 and 29, to enable the clamping face of the jaw to be moved angularly, in either direction, to accommodate irregularities and variations in parallelism, of the clamping edges of the workpieces, while holding the vertical plane of the jaw substantially perpendicular to the bar faces.

The adjustable jaw 23 may be attached to the necked down or unthreaded free end of the adjusting screw 24, by means of an opening formed in a boss 53, formed integral with the clamping wall of the jaw. A hollow-head or other suitable type of set-screw 54 may be threadably mounted in an extension 55 of the boss, the point of the screw, fitting a slot formed in the outer circumference of the end of the adjusting screw, to permit the adjusting screw to be rotated, while the jaw remains in a position substantially perpendicular to the bars, the slots 48, formed in the clamping wall of the adjustable jaw, retaining the vertical plane of the clamping face in a position substantially perpendicular to the bar faces. Clearance may be provided between the opening formed in the adjustable jaw boss 53, and the diameter of the attaching end of-the adjusting screw, to permit limited angular movement of the jaw in a direction perpendicular to the bar faces, to take up any irregularities, or variations in parallelism of the clamping dges of the work pieces.

Other suitable means of attachment of the adjustable jaw to the adjusting screw may be substituted, to increase or decrease the relative angular movement between the jaw and the adjusting screw, depending upon the accuracy of the work to be clamped.

The handle 39 may be made in one piece as indicated in Fig. 1, an opening formed in the hub 56, at the mounting end of the handle, being fitted over the threaded, unthreaded, or necked down outer end of the adjusting screw. 7 A pin 51 or other suitable locking means may be inserted through the mounting boss 56 of the handle, and the end of the adjusting screw, to positively locate the handle on the adjusting screw.

In place of the one-piece handle, a built-up handle may be utilized, with a tubular grip rotatably fitted to the gripping end 58 ofthe h die, to facilitate manual rotation of the handle and the adjusting screw.

A plurality of clamps may be built up, as indicated in Fig. 6, to accommodate a plurality of work-pieces 20 and 2|, 20a and 21a, and 20b and 21b, by adding additional bars 150 and GI to the bars in and H, of an individual clamp, a set of work-pieces being mounted between each pair of bars.

An additional fixed bracket t2a may be attached to the end of the bar It, opposite the bracket l2, the slot 15, in the upper end of the bracket, slidably supporting the adjacent bar 60.

An additional adjustable jaw 23a may be fitted to an adjusting screw 24a, threadably mounted inthe bracket 12a, between the bars l and $0, the control handle 39a. being located opposite the handle 39-, attached to the lower adjusting screw 24, as shown 'in Figs. 1 and 6, and hereinbefore described.

additional sliding bracket lBa may be mounted between the fixed bracket l2 and the edge of the work-pieces 20c, between the bars l0 and 60, with a pair of slots slidably supporting the bars Ill and 60, in the manner hereinbefore described.

The sliding bracket 48a, the pins 28, 29, 35 and 36, and the eccentric cams 3| and 32, fitted to the bracket 18a, are identical with those shown 'in Figs. 1, 2 and 4, and hereinbefore described.

It is thus possible to independently clamp one set of work-pieces between the bars l0 and II, and an additional set between the bars l0 and 60, by operating the adjusting screw handles 39 and 39a at opposite sides of the tiered multiple clamp unit of Fig. 6.

The relative position of the additional bar 60 may be moved upward, or downward, with relation to the bar ID, to accommodate thicker or thinner work-pieces, the alignment and substantial parallelism of the bars being maintained by the slots l5, I6 and [1, formed in the fixed bracket I2a and the sliding bracket l8a, respectively, as hereinbefore described.

The bars are gripped between adjacent eccentric cams 3| and 32, in the auxiliary sliding bracket assembly l8a, in the manner shown in Fig. 3 and hereinbefore described.

The number of bars, and consequently the number of additional clamps mounted in a set of tiered clamps, may be increased indefinitely within reasonable limits, by merely adding additional bars, above the bar 6!, attaching an additional fixed bracket [2 at the open end of the bar 8|, in Fig. 6, and adding additional brackets I2 and I8, respectively, as required.

In using a tiered set of clamps, as indicated in Fig. 6, the central work-pieces 20a and 2m, may be omitted, or inserted, or removed, independently of the work-pieces mounted in the clamps above or below them. Each set of jaws, located between each set of bars may be operated independently of the jaws located between the adjacent bars, or any other set of bars in the tier.

The distance between the bars may be varied considerably between each set, so that thicker or thinner sets of work-pieces may be clamped between each set of bars, regardless of the relative position of the bars in the adjacent clamps.

Where thick work-pieces are to be supported in a clamp, or a wide range of work piece thicknesses is to be accommodated, the height of the brackets I2 and I8, and consequently the depth of the bar slots l5, l6 and I! may be increased, to

'6 permit wider spacing between 'the bars, within the limitations of the eccentric cam spacing.

In order to increase the gripping pressure of the eccentric cams, against the bars, the face thickness of the cams 3| and 32 may be increased, thus increasing the area of engagement between the bars and the cams, in the clamping position.

Where still higher pressures are required, to supply increased pressures against thev glued joint, or to accommodate work pieces of exceptionally heavy thickness, additional cam slots may be provided in the sliding bracket '18, and additional rows of cams inserted, either between the cams 3 and 3| a, or beyond the cams 3| and 3-! a, thus gripping each bar, at two or more points in the clamping position.

The bars 10- and H, while shown of substantially rectangular cross-section may be made of square cross-section, or other suitable cross-section, the height of the bars varying with the span between the clamping elements, and the range of thickness of work-pieces to be accom modated.

The length of the bars may be increased, to accommodate wider sections of work-pieces, than those shown in the drawings, or tocla'mp an additional number of work-pieces between each set of bars.

The length and height of the clamping face "of the floating jaw, and similarly the length and height of the clamping face of the adjustable jaw may be increased, or decreased, to grip workpieces of increased length, or to accommodate thicker or thinner work-pieces, or a wider range of work-pieces.

Instead of being substantially flat, the clamping faces of the floating and adjustable jaws may be rounded, or otherwise contoured, to accommodate and accurately clamp work-pieces, the clamping faces, of which, are of special form or contour.

It will be apparent to those skilled in the art that my present invention is not limited to the specific details described above and shown in the drawings, and that various modifications are possible in carrying out the invention without departing from the spirit and scope of the appended claims.

What I claim is:

1. A clamp including a bar having thereon a fixed bracket and a sliding bracket in spaced relation longitudinally of the bar, an adjustable jaw movable longitudinally on the bar between said brackets, operating means carried by the fixed bracket for moving the adjustable jaw, a floating jaw movable on and with said sliding bracket in opposition to the adjustable jaw, gripping elements pivoted intermediate their ends on the sliding bracket at opposite sides of the bar, each gripping element having at its outer end a pivoted connection to the floating jaw and at its inner end a cam surface engaging a face of the bar, and both pivotal axes of each gripping element being parallel to the bar face engaged by its cam end.

2. A clamp comprising a pair of spaced parallel bars, a bracket fixed to one bar and slidably supporting the other, a bracket slidably engaging both bars, an adjustale jaw movable longitudinally of said bars, operating means carried by said fixed bracket for moving the adjustable jaw, a floating jaw movable on said sliding bracket, a gripping element pivoted intermediate its ends on the sliding bracket adjacent each bar on both sides of the bar, each gripping element having .at'its outer end a pivoted connection to said floating jaw and at its inner end a cam surface engaging a face of the adjacent bar, both pivotal axes of each gripping element being parallel to the bar face engaged by its cam end, and stop means on the slidably supported bar engageable with the fixed bracket on the other bar to limit movement of the slidably supported bar during closing movement of the clamp jaws.

3. A tiered clamp including a stack of spaced parallel bars each of which has adjacent one end a fixed bracket slidably supporting the adjacent end of the next succeeding bar, the positions of succeeding bars being relatively reversed to disposed alternate ones of the fixed brackets at opposite ends of the stack, a sliding bracket in each space between successive bars engaging both adjacent bars and cooperating with their fixed brackets to maintain the bars in spaced parallel relation, an adjustable jaw movable longitudinally of said bars in each space between successive'bars, operating means carried by each fixed bracket for moving its corresponding adjustable jaw, a floating jaw movable on and with the sliding bracket in each space between successive bars in opposition to its corresponding adjustable jaw, said sliding brackets carrying gripping elements disposed on opposite sides of the adjacent bars, the gripping elements being pivoted intermediate their ends on the sliding brackets, each gripping element having at its outer end a pivoted connection to the floating jaw of the slidable bracket on which the gripping element is mounted and having at its inner end a cam surface engaging a face of the adjacent bar, both pivotal axes of each gripping element being parallel to the bar face engaged by its cam end, and stop means on each successive bar engaging the fixed bracket on the immediately preceding bar to limit movement of said successive bars during closing movement between their associated jaws.

, MAX E. WEI'ZLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,126,116 Steuernagel Jan. 26, 1915 1,187,109 Steuernagel June 13, 1916 1,257,040 Steuernagel Feb. 19, 1918 1,628,479 Steuernagel May 10, 1927 1,712,142 Gaul May 7, 1929 2,359,235 Miller Sept. 26, 1944 FOREIGN PATENTS Number Country Date 28,244 Great Britain Dec. 23, 1904 

